The study indicates that there's still a lot of natural gas, which is selling near historic lows, to be profitably drilled in the Barnett. Gas prices just need to rise slightly from around $3.50 per million British thermal units to around $4.

That's good news for operators in the Barnett and elsewhere. But natural gas remains something of a product in search of a market.

Prices cratered a few years ago once shale drilling kicked up across the U.S. Unlike oil, which trades on a global market thanks to supertankers, natural gas is a local commodity now.

There's a lot of talk about using the natural gas reserves to power manufacturing and electricity generation.

He drives a car that takes natural gas, and last week paid $1.80 per gallon to fill up.

But he's able to do that because there's a network of gas stations in the Dallas-Fort Worth area that sell compressed natural gas for cars or trucks. And it's hard to justify adding those stations unless you already know there's a ready market willing to buy natural gas.

“It's a chicken or the egg situation,” Morgan said “If you go down the road in three to five years, it will be a no brainer. There's a breaking point where the public will want to switch, not just the fleets.”

Producers, who have been showing off natural gas vehicles at South Texas events recently, are banking on it.